The present invention concerns an admission control method of connections made up of one or several flows to a shared wireless medium, each connection requiring a predetermined target application Protocol Data Unit error rate and at least an additional quality of service requirement, the transmission on the shared wireless medium being adapted for transmitting frames of a predetermined maximum size, with a data link layer mean error rate, the method applying a criteria for each new connection to determine whether resources can be provided for this connection. We assume an ARQ (Automatic Repeat reQuest) algorithm to be implemented at the data link layer level.
Such a method is used for Admission Control of connections with Quality of Service requirements.
By connection we mean the route, established between two different network devices, dedicated to the transmission of one or several data flows. When a connection transports several flows, each data link layer Protocol Data Unit (PDU) may include data issued from different flows.
To reach the Quality of Service requirements, the admission control method accepts to establish a new connection only if the load associated with this new connection is lower than the remaining admissible capacity on each shared link. Given C is the total capacity of a link and ρ is its admissible load, the admissible capacity of this link is ρ×C. Assume there are k connections that are already established on the link, and connection i uses a bandwidth equal to D′i, then the remaining admissible capacity equals
      ρ    ×    C    -            ∑              i        =        1            k        ⁢                  D        i        ′            .      
Each connection may have 0, 1 or several quality of service requirements which are necessary for satisfying each user after reception of his flow.
For example, if an application generates a flow with a minimum throughput requirement, the data link layer shall provide a bandwidth at least equal to this throughput.
In addition, some frames can be erroneous. These frames have to be retransmitted by the ARQ algorithm in order to reach a target application PDU error rate.
In the known Admission Control Methods, no means is provided in order to be sure that the shared link capacity is sufficient to enable all the retransmissions necessary for each connection sharing the link to reach its target application PDU error rate.